1. Technical Field
This invention relates to a liquid crystal-containing composition, and a liquid crystal display device using the same.
2. Related Art
A cholesteric liquid crystal is composed of rod-like molecules that are aligned helically, and reflects light corresponding to the helical pitch thereof by interference (referred to as selective reflection). Therefore, when the helical pitch of a cholesteric liquid crystal is set to a pitch corresponding to the wavelength of red, green, or blue light, a vivid color display can be obtained without using a color filter.
In a cholesteric liquid crystal encapsulated in a cell provided with a pair of substrates each having an electrode, the cholesteric liquid crystal may be aligned in two states: planar (P) alignment or focal conic (F) alignment. The P alignment is a state in which the helical axis is aligned perpendicular to the substrate surface, and can cause selective reflection. The F alignment is a state in which the helical axis is aligned in parallel with the substrate surface, and can transmit light. The alignment state of the liquid crystal can be switched between these two states when a voltage is applied between the electrodes.
Therefore, when a light absorber, such as a black light absorber, is disposed on a back surface of the cell, a bright display exhibiting a selective reflection color is provided under the P alignment state, and a dark display exhibiting the black color of the light absorber is provided under the F alignment state. The P and F alignment states can be stably maintained without supplying power. A memory display which can maintain a display without supplying power thereto is achieved by utilizing such properties.